Method of utilizing offals for pet food manufacture

ABSTRACT

The invention involves a method for the recover of commercial slaughter waste streams for use in the manufacture of commercial pet food products, wherein waste materials are collected following the commercial slaughter of animals, the greater part of those materials being size reduced as necessary and heated, whereupon a proteinaceous fraction, lipidaceous fraction, and aqueous fraction are formed and substantially separated from one another and wherein each of said fractions are subsequently used in the production of commercial pet foods or components thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing of PCT/AU02/01030 filed Aug.1, 2002 claiming priority to Australian applications PR6801 filed Aug.3, 2001 and PR9860 filed Jan. 7, 2002.

TECHNICAL FIELD

The present invention is directed to a method for the recovery ofcommercial slaughter waste streams for use in the manufacture ofcommercial pet food products.

BACKGROUND OF THE INVENTION

Petcare companies have for many years provided commercial petfoods tovarious markets around the world. Commercial petfood products aredesigned to be nutritious, but are also required to be highly palatableto ensure the animal consumes sufficient volume to receive itsnutritional requirements, and to ensure the pet owner is satisfied thatthe product is ‘satisfying’ the animal's needs.

One of the aesthetic drawbacks of traditional commercial petfoods isthat they have been perceived by pet owners as ‘artificial’, and byinference, not as healthy or satisfying for the animal. This perceptionmay exist quite independently of the actual nutritional or sensoryperformance of the products.

Therefore, to enhance the owner's perception of these products, therehas always been a need to provide a ‘meat-like’ texture in commercialpetfoods, in order to provide ‘real food’ cues to the owner of the petand to provide satisfying texture to the animal.

To provide the ‘muscle meat’ texture that is desirable, but on acost-effective basis, commercial petfood manufacturers have developedvarious technologies to make manufactured meat analogues, or meat-likechunks. This is often done by utilizing the binding functionality ofselected raw material to form an integral mass from comminuted meatand/or cereal slurries via various processes. The recent evolution ofthis technology is summarized as follows:

1970's

Lower-moisture extruded vegetable protein has been used as a ‘chunk’ inpackaged foods. It has a ‘meaty’ internal texture, but does not havegood palatability, particularly for felines. Also, the requirement forhigh levels of sulfur in the recipe is a drawback in relation to itsundesirable impact on the product and packaging aesthetics.

Meat slurries were created from low-grade meat offals, cooked in gasovens and cut into chunks. However, these chunks tended to be not aspalatable as muscle meat and did not display a satisfactorily ‘meaty’internal texture.

Lung lobes have been cut to resemble muscle meat. However the sortingand trimming required to obtain the lobes themselves, as well as thepoor recovery of lung chunks through high-volume size reductionprocesses, and the further poor recovery of chunk size post canning, aresignificant drawbacks for this technique.

1980's

Meat analogue chunks manufactured from meat slurries were made resilientvia the use of materials with binding properties such as cerealstarch/konjac/alginate/pectin. However, many of these chunks lackedrealistic texture, especially internally. Some of the binders alsotended to be relatively expensive.

1990's

‘Steam-Set Meat’ (SSM) chunks formed from slurries cooked in steam ovensand cut into chunks, particularly utilizing the water binding ability ofsuch materials as egg white, blood plasma, soy protein isolate, selectedchicken pieces, cereal binders and gelling agents to provide resilience.The chunks themselves were not superior to the gas-oven chunks, howeverthis technique was preferred to gas-oven cooking due to the eliminationof fires and due to lower maintenance costs.

SSM chunks are also prone to degradation during mixing and fillingoperations, and lack a realistic ‘meaty’ internal texture. They alsorequire a complex multi-stage manufacturing process, and depend on thebinding ability of high cost ingredients such as blood plasma and wheatgluten and muscle meats for resilience.

2000's

Utilisation of higher-moisture extrusion techniques to create a HigherMoisture Extruded Chunk (HMEC) that is highly digestible and palatable,yet resilient during mixing and filling operations. One such operationis described in PCT Patent Application No. PCT/AU00/00475, in the nameof Effem Foods Pty Ltd. The resultant product is capable of replicatingthe textured appearance of beef, lamb, chicken and fish. It will beunderstood by those skilled in the art that reference to‘higher-moisture extrusion’ encompasses extrusion cooking of materialshaving an overall moisture content of greater than about 30% by mass.

However, one of the requirements of successful higher-moisture extrusionis that the proteinaceous feed stream is low in fat and ideally also lowin water. The type of higher-moisture and/or high fat slurriestraditionally used for meat-based chunks tends to be too low inviscosity for extrusion. Technically, this may be overcome by theaddition of high-grade protein sources such as wheat gluten, soy proteinand spray-dried egg white, as well as other high-cost, low-fat meatstreams such as liver. However, these materials are too high in cost tobe contemplated for the vast majority of commercial petfood products.

For a commercial pet food manufacturer to improve the utilization of theabove described HMEC and SSM technologies in packaged pet foods, it isaccordingly desirable to ameliorate some or all of the disadvantages ofthese technologies.

In parallel, the development of lower-moisture extruded commercial petfoods has driven a demand for:

tallow as a palatability and fat source to provide sufficient dietaryenergy in an otherwise mainly cereal-based product; and

Palatable, aqueous coatings that may be sprayed on to the extrudedkibbles to improve their palatability.

It will be understood by those skilled in the art that reference to‘lower-moisture extrusion’ encompasses extrusion cooking of materialshaving an overall moisture content of less than about 30% by mass.Similarly, ‘lower moisture foods’ are equivalent to food materialshaving a moisture content of less than about 30% by mass.

It will further be understood by those skilled in the art that referenceto ‘higher-moisture extrusion’ encompasses extrusion cooking ofmaterials having an overall moisture content of greater than about 30%by mass. Similarly, ‘higher moisture foods’ are equivalent to foodmaterials having a moisture content of greater than about 30% by mass.

Tallow is typically obtained from commercial rendering plants, wheremammal by-products not directed to the human or pet foods streams areprocessed. Recently, however, concerns have grown regarding theintroduction of ‘specific risk materials’ (SRM's) into the mammalianfood stream. These materials include spleen, brain, and spinal cord, andare associated with degenerative diseases such as Bovine SpongiformEncephalopathy (BSE). As these materials are often processed byrenderers, there is a significant risk that these materials may beincorporated into commercial lower-moisture petfoods, with a potentiallong-term health risk for the animal. Therefore, it would beadvantageous to develop an alternative, low-cost fat source that is freeof BSE risk.

In parallel with the above issues, there is a desire to improve theprofitability of commercial pet food operations by reducing the expenseand complexity of the red meat, chicken and fish supply chain. A typicalflow chart for the red meat supply stream to a commercial pet foodmanufacturer is shown in FIG. 1.

Typically, bovine, ovine and porcine materials are directed to one ofthree main streams at the abattoir: ‘human consumption’, ‘petfood only’and ‘condemned’. The mixed organs of the petfood stream are directed tolarge bins.

At the collector, usually a separate plant to the abattoir and thepetfood manufacturer, the petfood offal bins are sorted into theircomponents such as lung, liver, hearts, kidneys and others with theremaining material stream called offcuts. Offcuts may include: musclemeat trims, tongue roots, trachea, gullets, weasands, liver, lungoff-cuts, hearts, kidney, pig testes, pig skin and blooded lung lobetrims, among other things. Considerable expenses are incurred inrefrigerated storage and transport of the mixed offal from abattoir tocollector, manual sorting and trimming of various organs at thecollector, and subsequent frozen storage and transport to the petfoodmanufacturer. Therefore, there would be considerable advantage inremoving or reducing the petfood manufacturer's reliance on thecollector. However, there are some obstacles to be overcome in doingthis.

In the past, there were no chunk manufacturing technologies that couldsuccessfully utilize unsorted, or only partially sorted, red meatorgans. Sorting allows the particular properties of particular organs tobe specifically utilized in the pet foods products, both in chunks andin the ‘background’ of the petfoods, while allowing the diversion oftroublesome ingredients such as offcuts away from the criticalmanufacturing processes and products. The typical distribution of thesesorted materials in a commercial packaged petfood manufacturing processis illustrated in FIG. 2. It will be understood by those skilled in theart that reference to ‘packaged’ petfoods is also intended to encompassall packaging formats in which commercially sterilised, higher-moisturepetfoods are packaged. These other packaging formats may include sealedaluminium trays and sealed pouches made from flexible films. The typicaldistribution of these sorted materials in a commercial lower-moisturepackaged petfood manufacturing process is illustrated in FIG. 3.

The offcuts stream is extremely variable, particularly in fat level(typical range is 10%-40% but may vary outside these limits). Thisvariability limits its use in chunk manufacture and canning processesdue to the interference of the fat on the protein setting process, whichin turn has an adverse effect on the product aesthetics. The “cookout”which occurs from this material during canning also tends to degrade theappearance of the product.

As described above for red meats, chicken and other poultry-basedmaterials undergo multiple process, storage and transport stages inbetween slaughter and the petfood manufacturer. This significantly addsto the effective cost of these materials to the petfood manufacturer.The typical chicken material collection process is shown in FIG. 4.

These materials are received as either ‘Chicken Offals’—a stream ofheads, feet, bones and viscera in varying ratios, and hence variable fatand moisture content, or as ‘Chicken Pieces’—chicken frames and otherwhole chicken components which, while they may vary in composition, arevaluable due to the functionality of the protein contained therein. Thisfunctionality could potentially be used to reduce reliance on expensivefunctional protein isolates, such as egg white powder, blood plasma andsoy protein isolate. However, inherent variations in fat and moisturetend to interfere with the functionality of the protein.

Therefore, it is desired to provide a method of more efficientlycollecting and processing red meat and poultry offal, in order tofacilitate the improved quality and cost-effectiveness of commercialpetfood manufacture.

BRIEF SUMMARY OF THE INVENTION

In a first aspect, the invention provides a method for the recovery ofcommercial slaughter waste streams for use in the manufacture ofcommercial pet food products, wherein; waste materials are collectedfollowing the commercial slaughter of animals selected from the groupconsisting of bovine mammals, ovine mammals, porcine mammals, poultryand fish; the greater part of those materials are size-reduced asnecessary; then heated; whereupon the proteinaceous fraction,lipidaceous fraction and aqueous fraction are substantially separatedfrom one another; and wherein each of the proteinaceous fraction,lipidaceous fraction and aqueous fraction are subsequently used in theproduction of commercial pet foods or components thereof.

The homogenization of all of the waste materials, followed by separationof the materials into specific functional fractions, based oncomposition, provides the petfood manufacturer with greater control overthe performance of these slaughter by-product materials duringsubsequent processing into petfood items. The issue of the variablewater/fat/protein content of the individual sorted organs and off-cutsmay be reduced or eliminated. This also reduces or eliminates the needfor costly manual sorting of the abattoir by-products into individualorgans. For example, the inefficient process of creating lung lobechunks may be replaced by feeding some of the materials produced by theinvention into a better-controlled analogue chunk process, such as theHMEC process.

Advantageously, the materials may be acidified prior to the separationstage. This may improve the separation of water and fat from theproteinaceous material. Acidification may also improve the floor-life ofthe fractions and may have a positive effect on the palatability of thefinal food products. Preferably, the material is acidified to a pH ofbetween 1.5 and 5.0, with a preferred target pH range of 2.5 to 4.0.

The materials may be initially separated into a proteinaceous fraction,and a combined lipidaceous and aqueous fraction, existing as a stableemulsion. Advantageously, this combined lipidaceous and aqueous fractionmay be used as an energy source and/or as a palatability-enhancer in themanufacture of lower-moisture extruded pet foods or components thereof,or as a palatability-enhancing ingredient in canned pet foods.

Advantageously, the lipidaceous fraction may be used as an energy sourceand/or as a palatability-enhancer in the manufacture of lower-moistureextruded pet foods or components thereof.

Advantageously, the aqueous fraction may be used as a coating in themanufacture of lower-moisture extruded pet foods or components thereof.It may be used ‘as is’, or concentrated prior to coating on the petfoods.

Advantageously, the proteinaceous fraction may be used in themanufacture of texturized, lower-moisture extruded pet foods orcomponents thereof.

Advantageously, the proteinaceous fraction may be incorporated as aprotein source in the manufacture of higher-moisture, extruded meatanalogue chunks for incorporation into commercial packaged pet foods orcomponents thereof.

Advantageously, the proteinaceous fraction may be incorporated as aprotein source in the manufacture of lower-moisture, extruded meatanalogue chunks for incorporation into commercial packaged pet foods orcomponents thereof.

Advantageously, the proteinaceous fraction may be incorporated as afunctional binding protein source in the manufacture of higher-moisturemeat analogue chunks for incorporation into commercial packaged petfoods or components thereof.

Advantageously, the proteinaceous fraction may be dried to a moisturecontent of approximately <15%. This may improve its floor life as itawaits further processing.

Advantageously, the proteinaceous fraction may be incorporated as apalatant in the background meat matrix of higher-moisture commercialpackaged pet foods.

Preferably, and especially for mammal-sourced materials, thesize-reduction is carried out as coarse grinding followed by finegrinding. The coarse grinding may be carried out via a continuous meatgrinder, such as those manufactured by e.g. Weiler & Co., or Wolfking &Co. Preferably, the feed screw may be selected from standard typessuitable for frozen or fresh materials, depending on what feed is used.Preferably, the holeplate hole sizes are between 3 mm and 10 mm.

The fine grinding, or emulsification, is performed by a standard meatslurry emulsification unit, for example those machines manufactured byKarl Schnell or Wolfking & Co. Preferably, the holeplate hole sizes arebetween 1.7 mm and 6.0 mm. Preferably, output temperature from the finegrinding unit operation should not exceed 25-35° C.

Where the proteinaceous fraction is to be used in the manufacture ofmeat analogue chunks, or jerky-style snacks, the emulsified material ispreferably heated to within the range 35-60° C., and advantageously towithin the range 40-50° C., in order to preserve protein functionality.Where the proteinaceous fraction is to be used in the manufacture ofhigher-moisture, or lower-moisture, extruded meat analogue chunks, theemulsified material is preferably heated to within the range 40-140° C.,and advantageously to within the range 45-100° C. The material may beheated either continuously or in a batch process. The material may beheated by direct steam injection into a mixing vessel, or by heattransfer via an indirect heating method, such as a heat exchanger.

Preferably, a separation process utilizing centrifugal force may be usedto separate the proteinaceous, lipidaceous and aqueous phases. Apreferred type is a decanter centrifuge such as those supplied by AlfaLaval, or Westfalia Separator. Separation of the three phases may beperformed as a single or two-stage unit operation. If a single unitoperation is chosen a decanter centrifuge designed to separate a singlefeed stream into three product streams is preferred. If a two-stageoperation is chosen, it is preferred to first separate the proteinaceousstream form the aqueous/lipidaceous stream, subsequently separating theaqueous and lipidaceous streams. The feed rate to the separator may bebetween 500-20,000 kg/h depending on size of decanter chosen and outputrequired.

The aqueous fraction should preferably be concentrated to a solids levelof 5-30%, or by a factor of between 1× to 7×, according to itsapplication. A number of suitable unit operations may be used. Twopreferred methods include centrifugation and evaporation.

A flow chart of a process embodying the invention is given in FIG. 5.

In another aspect, the invention provides a viscous, high-proteinsubstrate for the manufacture of packaged commercial pet foods, orcomponents thereof, wherein waste materials are collected from thecommercial slaughter of one or more animals selected from the groupconsisting of bovine mammals, ovine mammals, porcine mammals poultry andfish, the greater part of those materials are size-reduced as necessary;then heated, whereupon the proteinaceous fraction, lipidaceous fractionand aqueous fraction are substantially separated from one another in aseparation unit operation; and wherein the proteinaceous fraction issubsequently used as a component in the production of packagedcommercial pet foods, or components thereof.

The proteinaceous fraction advantageously provides a suitable highviscosity, reduced-fat protein source for the efficient andcost-effective higher-moisture extrusion of fibrous-textured meatanalogue chunks. Preferably this fraction may be diverted to a meatanalogue process, for example the hereinbefore-described HMEC process.This material will tend to be sufficiently palatable and will havesufficient viscosity to promote effective higher-moisture extrusion.This material may also be used as a major component in the manufactureof meat-based snack foods, e.g. jerky-style snack products for petmammals. The material will advantageously be highly palatable and leadto the production of highly palatable meat analogues, assisting inreducing reliance on individual livers as palatability enhancers, assorted by collectors.

The waste materials may be made up of any combination of red meat,poultry or fish. For example, if fish materials (e.g. whole whiting) areused, the invention provides the opportunity to produce a textured, fishanalogue chunk that contains a high percentage of fish material, byfeeding the proteinaceous fraction through e.g. the HMEC process. Theproteinaceous fraction according to the invention may advantageouslyincluded in the HMEC process feed at up to 95% by weight.

Some commercial packaged petfood products feature lower-moistureextruded chunks as internal components. The proteinaceous fraction mayadvantageously be used as a palatable protein source to wholly orpartially replace non-meat protein sources, such as wheat gluten, inthese products. The proteinaceous fraction according to the inventionmay advantageously included in such chunks at up to 50% by weight.

Preferably the proteinaceous fraction possesses the followingapproximate composition:

Protein: 15-40%

Moisture: 50-75%

Fat: 1-15%

Advantageously, said proteinaceous fraction possesses the followingapproximate composition:

Protein: 25-35%

Moisture: 60-70%

Fat: 1-8%

Or if dried:

Protein: 60-80%

Moisture: 5-15%

Fat: 5-20%

In another aspect, the invention provides an energy source forlower-moisture extruded commercial petfoods, or components thereof,wherein waste materials are collected from the commercial slaughter ofone or more animals selected from the group consisting of bovinemammals, ovine mammals, porcine mammals poultry and fish, the greaterpart of those materials are size-reduced as necessary; then heated,whereupon the proteinaceous fraction, lipidaceous fraction and aqueousfraction are substantially separated from one another in a separationunit operation, and wherein said lipidaceous fraction is incorporated inextruded lower-moisture kibbles used as components in the production ofcommercial pet foods.

Advantageously, said lipidaceous fraction provides a palatable energysource for incorporation into commercial petfoods, which is not sourcedfrom a renderer. This would assist in ensuring that the commercialpetfood does not carry a risk of promulgating degenerative diseases,such as BSE, that are associated with by-products of commercialrendering operations. Said lipidaceous fraction could advantageously besupplied to the petfood manufacturing process at a lower cost than acommercially rendered tallow, on at least a ‘unit cost per unit energy’basis.

Preferably the lipidaceous fraction possesses the following approximatecomposition:

Protein: 0-5%

Moisture: 0-5%

Fat: 90-100%

Advantageously, said lipidaceous fraction possesses the followingapproximate composition:

Protein: 0-1%

Moisture: 0-1%

Fat: 98-100%

In another aspect, the invention provides a coating for lower-moistureextruded commercial pet foods, or components thereof, wherein wastematerials are collected from the commercial slaughter of one or moreanimals selected from the group consisting of bovine mammals, ovinemammals, porcine mammals poultry and fish, the greater part of thosematerials are size-reduced as necessary; then heated, whereupon theproteinaceous fraction, lipidaceous fraction and aqueous fraction aresubstantially separated from one another in a separation unit operation,whereupon the aqueous fraction is concentrated; and wherein saidconcentrate is then sprayed on to the surface of lower-moisture kibblesused as components in the production of lower-moisture extruded drycommercial pet foods.

Advantageously, said concentrated aqueous fraction provides apalatability enhancement for incorporation into commercial petfoods,which is not sourced from a renderer. This would assist in ensuring thatthe commercial petfood does not carry a risk of promulgatingdegenerative diseases, such as BSE, that are associated with by-productsof commercial rendering operations.

Preferably, the aqueous fraction possesses the following approximatecomposition:

Protein: 0-5%

Moisture: 90-100%

Fat: 0-5%

Advantageously, said aqueous fraction possesses the followingapproximate composition:

Protein: 0-3%

Moisture: 94-100%

Fat: 0-3%

In another aspect, the invention provides a source of functionalproteins for assisting in developing resilience in meat analogueproducts for use in commercial packaged pet foods, or componentsthereof, wherein waste materials are collected from the commercialslaughter of one or more animals selected from the group consisting ofbovine mammals, ovine mammals, porcine mammals poultry and fish, thegreater part of those materials are size-reduced as necessary; thenheated, whereupon the proteinaceous fraction, lipidaceous fraction andaqueous fraction are substantially separated from one another in aseparation unit operation, wherein said proteinaceous fraction isincorporated in meat analogue products for use in commercial packagedpet foods, or components thereof.

The ground material is preferably heated to a temperature within therange 40-50° C. in order to preserve protein functionality. Thismaterial may advantageously be used to partially or wholly replace morecostly protein isolates, such as spray-dried blood plasma and wheatgluten in the manufacture of meat analogue chunks. For this application,the waste materials are preferably sourced from poultry.

The invention will now be further explained by way of a specificnon-limiting example of a method of utilizing commercial abattoir wastestreams for commercial pet food manufacture, according to the invention.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a flow chart of a typical red meat collection process;

FIG. 2 is a flow chart of a typical packaged pet food manufacture;

FIG. 3 is a flow chart of a typical lower-moisture pet foodmanufacturing process;

FIG. 4 is a flow chart of a typical chicken collection process; and

FIG. 5 is a flow chart of an embodiment of the process according to theinvention.

DETAILED DESCRIPTION OF THE INVENTION

At the commercial abattoir, unsorted pet food grade offals, as per thosediscussed above in the prior art, are collected in bins according tonormal practices. These bins are shipped to the site of the commercialpet food manufacturer. The offals may be chilled to below 10° C.,depending on the length of the transport chain.

Once received, the offals are ground through a continuous meat grinder,such as those manufactured by e.g. Weiler & Co., or Wolfking & Co.,having a feed screw of a standard type suitable for frozen or freshmaterials, and a holeplate hole size are between 3 mm and 10 mm.

The offals are then ground through a fine grinder, such as a meat slurryemulsification unit, for example those machines manufactured by KarlSchnell or Wolfking & Co. The holeplate hole sizes recommended for thisoperation are between 1.7 mm and 6.0 mm. The target output temperatureof the material exiting this fine grinding unit operation should notexceed 25-35° C.

At this point, the materials may be acidified, in order to improve thesubsequent separation of water and fat from the proteinaceous material.Acidification may also improve the floor-life of the fractions and mayhave a positive effect on the palatability of the final food products.This can be done via the addition of a simple food-grade acid such asHydrochloric Acid, diluted sufficiently to avoid denaturation ofproteins on contact. This may be done while the slurry is agitated in astirred and/or recirculated vessel, or may be done via ‘in-line’injection of acid into the stream exiting the fine grinding operation.The target pH range is between 2.5 to 4.0.

Where the proteinaceous fraction is to be used in the manufacture ofmeat analogue chunks, or jerky-style snacks, the emulsified material isheated to within the range 35-60° C., and advantageously to within therange 40-50° C., in order to preserve protein functionality. Where theproteinaceous fraction is to be used in the manufacture ofhigher-moisture, or lower-moisture, extruded meat analogue chunks, theemulsified material may be heated to within the range 40-140° C., andadvantageously to within the range 45-100° C. The material may be heatedeither continuously or in a batch process. The material may be heated bydirect steam injection into a mixing vessel, or by heat transfer via anindirect heating method, such as a heat exchanger.

The proteinaceous, lipidaceous and aqueous phases are separated bypassing the slurry through a decanter centrifuge such as those suppliedby Alfa Laval, or Westfalia Separator. Separation of the three phasesmay be performed as a single or two-stage unit operation. If a singleunit operation is chosen a decanter centrifuge designed to separate asingle feed stream into three product streams is preferred. If atwo-stage operation is chosen, it is preferred to first separate theproteinaceous stream form the aqueous/lipidaceous stream, subsequentlyseparating the aqueous and lipidaceous streams. The feed rate to theseparator may be between 500-20,000 kg/h depending on size of decanterchosen and output required.

The aqueous fraction should preferably be concentrated to a solids levelof 5-30%, or by a factor of between 0× to 7×, according to itsapplication. A number of suitable unit operations may be used. Twopreferred methods include centrifugation and evaporation.

A flow chart of a process embodying the invention is given in FIG. 5.

The proteinaceous fraction exiting the centrifuge should have thefollowing approximate composition: Protein: 25-35%; Moisture: 60-70%;Fat: 1-8%.

If desired, the proteinaceous fraction may be dried to a composition of:60-80%; Moisture: 5-15%; Fat: 5-20%.

The lipidaceous fraction exiting the centrifuge should have the ngapproximate composition: Protein: 0-1%; Moisture: 0-1%; Fat: 98-100%.

The aqueous fraction exiting the centrifuge should have the followingmate composition: Protein: 0-3%; Moisture: 94-100%; Fat: 0-3%.

1. A method for the recovery of commercial waste parts for use in themanufacture of commercial pet food products, comprising the steps of:collecting waste parts selected from the group consisting of hearts,kidneys, lungs, liver, spleen, tripe, meat offcuts, chicken viscera,chicken heads and feet, chicken pieces, and chicken necks from thecommercial processing of animals; size-reducing the waste parts bygrinding to produce an emulsified material; heating said the emulsifiedmaterial; substantially separating the proteinaceous fraction from thelipidaceous and aqueous fractions; substantially separating thelipidaceous and aqueous fractions from one another; wherein theproteinaceous, lipidaceous and aqueous fractions are each subsequentlyused in the production of commercial pet foods or components thereof. 2.The method of claim 1, wherein the emulsified material is acidified to apH of between 1.5 and 5.0 prior to the separation stage.
 3. The methodof claim 1, wherein the proteinaceous fraction is used in themanufacture of texturised extruded pet foods or components thereof. 4.The method of claim 1, wherein the proteinaceous fraction isincorporated in the manufacture of extruded meat analogue chunks forincorporation into commercial packaged pet foods or components thereof.5. The method of claim 1, wherein the proteinaceous fraction isincorporated as a functional binding protein source in the manufactureof meat analogue chunks incorporated into commercial packaged pet foodsor components thereof.
 6. The method of claim 1, wherein theproteinaceous fraction is incorporated as a palatant in the backgroundmeat matrix of commercial packaged pet foods.
 7. The method of claim 1,wherein the proteinaceous fraction is dried to a moisture content of<15%.
 8. The method of claim 1, wherein output temperature from thesize-reduction operation does not exceed 35° C.
 9. The method of claim1, wherein the size-reduced material is heated to within the range of35-60° C.
 10. The method of claim 1, wherein a separation processutilizing centrifugal force is used to separate the proteinaceous,lipidaceous and aqueous phases.
 11. The method of claim 2, wherein thewaste materials are acidified to a pH of between 2.5 to 4.0, prior tothe separation stage.
 12. The method of claim 9, wherein the fine-groundmaterial is heated to within the range of 40-50° C.
 13. The method ofclaim 1, wherein the waste parts are selected from the group consistingof bovine mammals, bovine mammals, porcine mammals, poultry and fish.